Most retirement advice throws around intimidating numbers. You'll hear you need **$1. 5 million** or **$2 million** to retire comfortably.
But the actual number depends entirely on one thing: how much you plan to spend.
The 4% Rule gives you a simple way to work backward from your spending to your target nest egg. No guesswork. Just math — and it might reveal you need less than you think.
What is the 4% Rule and how does it work?
The 4% Rule comes from the landmark Trinity Study. It found that a balanced portfolio withdrawing 4% of its starting value annually (adjusted for inflation each year) historically lasted **30 years or more** without running out.
The math is simple: multiply your desired annual retirement income by 25. Want **$60,000** per year? You need **$1.
5 million**. Want **$40,000** per year? You need **$1 million**.
Divide your target spending by 0. 04, and you get your number.
The 4% withdrawal rate has survived every market cycle in modern US history, including the Great Depression, the 1970s stagflation, the 2008 financial crisis, and the 2022 bear market.
What is your FIRE number?
The FIRE (Financial Independence, Retire Early) movement popularized this simple formula. Your FIRE number is **annual expenses × 25**. If you spend **$50,000** per year, your FIRE number is **$1.
25 million**.
Variations include Lean FIRE (under **$40,000/year** spending), Fat FIRE (over **$75,000/year**), and Coast FIRE — where you've saved enough that your nest egg will reach your FIRE number by traditional retirement age without further contributions.
Find Your Retirement Number Today
Enter your age, current savings, monthly contributions, and target retirement age to see your projected nest egg. Our calculator uses the 4% Rule to show whether you're on track or need to adjust.